TWI414558B - A polycarbonate resin composition and a molded article - Google Patents

Abstract

A polycarbonate resin composition excelling in weld strength composed of 60 to 95 pts.wt. of aromatic polycarbonate resin (a); 4 to 39 pts.wt. of styrene/(meth)acrylonitrile copolymer (b) obtained by polymerization of at least a styrene monomer and a (meth)acrylonitrile monomer in the presence of a rubber; 1 to 36 pts.wt. of styrene/(meth)acrylonitrile copolymer (b') obtained by polymerization of at least a styrene monomer and a (meth)acrylonitrile monomer in the absence of any rubber; 0 to 40 pts.wt. of phosphorus flame retarder (c); 0 to 5 pts.wt. of fluorinated polyolefin (d); and 0 to 50 pts.wt. of inorganic filler (e), characterized in that when the ratio of total weight of components (b)+(b') to total weight of components (a)+(b)+(b') is referred to as B wt.%, the average occupancy area Sd (µm<SUP>2</SUP>) of styrene/(meth)acrylonitrile copolymer domain (referred to as "AS domain") dispersed in polycarbonate resin matrix and the average occupancy area Sg (µm<SUP>2</SUP>) of rubber particles dispersed in the AS domain, measured by image processing of an electron micrograph of the composition satisfy the relationship of the formula: Sg/(Sd/B<SUP>2/3</SUP>) = 0.5 (1).

Description

Polycarbonate resin composition and molded article thereof

The present invention relates to a polycarbonate resin composition, and more particularly to a polycarbonate resin composition having improved weld strength and a molded article thereof.

In the past, polycarbonate resins have excellent mechanical properties, and are widely used on industrial scale as raw materials in the automotive field, OA (office automation) equipment, electrical and electronic fields, but have high melt viscosity. Poor fluidity, or the impact strength is limited by thickness. In order to ensure fluidity, a method of using a polycarbonate having a low molecular weight or a method of blending various fluidity modifiers may be exemplified, and although there is an improvement in fluidity, there is a need for sacrificial polycarbonate. The ester has inherent disadvantages such as impact strength and chemical resistance. Then, a styrene resin such as an ABS resin (acrylonitrile-butadiene-styrene copolymer) is blended to try to improve these disadvantages.

A thermoplastic resin composition made of a polycarbonate or a styrene resin is used in large-sized molded articles such as automobiles and OA equipment, and small-sized molded articles such as mobile end machines. These products are thinned out year by year for the purpose of light weight and high functionality. For the resin itself, the liquidity is better, and in terms of design, the multi-gate is used. (gate). In particular, if a molded article is to be obtained by a multi-point gate method, the molten resin will merge at the time of molding. In other words, the thermoplastic resin composition formed of the polycarbonate and the styrene resin is present in the strength of the welded portion (hereinafter referred to as "welding strength"), particularly, at the time of staying. The welding strength will be significantly reduced.

For the purpose of improving the weld strength in a molded article containing a resin composition of a polycarbonate and an ABS resin, Patent Document 1 discloses a method of using a polycarbonate having a specific terminal group, but not for the ABS resin. A description of the relationship between monomer composition or morphology and weld strength. Further, even if the resin composition containing the polycarbonate and the ABS resin having the above specific terminal groups is contained, the welding strength is not improved at all.

Patent Document 2 discloses a thermoplastic resin composition composed of polycarbonate and a styrene resin which is excellent in welding strength, rib strength, and transcriptional property, and has a specific viscoelasticity. The method of polycarbonate is the same as that of Patent Document 1, and there is no description of the specific relationship between the monomer composition, morphology, and weld strength of the ABS resin.

In addition, in the rubber-reinforced vinyl resin to which a rubber-reinforced vinyl resin/PC (polycarbonate)/scaly filler is blended, the weight average particle diameter is 0.1 μm or more, The fact that a combination of a small particle size rubber of less than 0.3 μm and a large particle size rubber having a weight average particle diameter of 0.3 μm or more and 2 μm or less is useful, but there is no relationship between the monomer composition or the morphology and the weld strength. Recorded. Further, in Patent Document 3, not only the measurement method of the average particle diameter is described at all, although the weight is In terms of average particle size, there is no mention of its definition. Therefore, in the invention described in Patent Document 3, it is completely unknown what kind of rubber is used in the proposal.

Patent Document 1: Japanese Patent Special Publication No. 7-98892

Patent Document 2: Japanese Patent Laid-Open No. 2003-20395

Patent Document 3: Japanese Patent No. 3384902

An object of the present invention is to provide a polycarbonate resin composition excellent in weld strength and a molded article thereof. In particular, by using an AS resin (acrylonitrile-styrene copolymer or the like) as a styrene resin blended with polycarbonate and using an ABS resin, it is possible to solve the problem that the fluidity can be improved, but the weld strength is lowered. Composition.

The present invention has been made in order to solve the above problems, and is a polycarbonate resin composition and a molded article thereof, which are (a) 60 to 90 parts by weight of an aromatic polycarbonate resin, and (b) rubber (rubber). In the presence of at least styrene-based monomer and (meth)acrylonitrile-based monomer, 4 to 39 parts by weight of the styrene/(meth)acrylonitrile-based copolymer, (b') is not present in the rubber At least 100 parts by weight of a total of 1 to 36 parts by weight of a styrene/(meth)acrylonitrile-based copolymer obtained by polymerizing a styrene monomer and a (meth)acrylonitrile-based monomer to prepare (c) phosphorus 0 to 40 parts by weight of the flame retardant, (d) 0 to 5 parts by weight of the fluorinated polyolefin, and (e) 0 to 50 parts by weight of the inorganic filler to form a polycarbonate resin composition, which is characterized by: When the total weight ratio of the component (b) component + (b') component of the total weight of the component (a) component + (b) component + (b') component is Bwt%, the electron micrograph image processing of the composition is performed. The average occupied area of the styrene/(meth)acrylonitrile-based copolymer domain (hereinafter referred to as "AS field") dispersed in the polycarbonate resin matrix measured later Sd (μm ^2), the AS and the average area of the dispersed rubber particles occupied area Sg (μm ²⁾ can meet the following relation (1).

[Number 1] Sg / (Sd / B ² / ³ ) ≧ 0.5 (1)

The polycarbonate resin composition of the present invention is superior to fluidity and weld strength, and is useful as a large-sized molded article or a thin-walled molded article in the field of electric and electronic equipment or precision machinery.

[Best Embodiment of the Invention]

Hereinafter, the contents of the present invention will be described in detail.

(a) Aromatic polycarbonate resin:

In the (a) aromatic polycarbonate resin of the present invention, an aromatic dihydroxy compound or a compound of this kind and a small amount of a polyhydroxy compound may be reacted with phosgene or a carbonic acid diester. A branched thermoplastic polymer or copolymer. Polycarbonate resin manufacturing method, not It is particularly limited, and may be in accordance with phosgene method (interfacial polymerization) or melt method (ester interchange). Further, it may be a polycarbonate resin produced by adjusting the amount of OH groups of the terminal groups after being produced by a melt method.

The blending amount of the aromatic polycarbonate resin is (a) an aromatic polycarbonate resin, and (b) at least a styrene monomer and a (meth)acrylonitrile monomer are polymerized in the presence of a rubber. a styrene/(meth)acrylonitrile-based copolymer, and (b') polymerize at least a styrene monomer and a (meth)acrylonitrile monomer in the absence of rubber to form styrene/( The total of 100 parts by weight of the methyl)acrylonitrile-based copolymer is 60 to 95 parts by weight, preferably 65 to 90 parts by weight. When the blending amount of the aromatic polycarbonate resin exceeds the upper limit, the fluidity is liable to lower, and if the lower limit is not reached, the heat resistance is liable to lower.

The aromatic dihydroxy compound may, for example, be 2,2-bis(4-hydroxyphenyl)propane (=bisphenol A), tetramethylbisphenol A or bis(4-hydroxyphenyl)-p-pair. Isopropylbenzene, hydroquinone, resorcinol, 4,4-dihydroxybiphenyl, etc., preferably bisphenol A. Further, as the above aromatic dihydroxy compound, one or more compounds in which a tetraalkylsulfonium sulfonate is bonded may be used.

When a branched aromatic polycarbonate resin is to be produced, it is 1,3,5-benzenetriol (phloroglucin), 4,6-dimethyl-2,4,6-tris(4-hydroxybenzene). Heptene-2,4,6-dimethyl-2,4,6-tris(4-hydroxyphenyl)heptane, 2,6-dimethyl-2,4,6-tris(4- a polyhydroxy compound such as hydroxyphenyl)heptene-3, 1,3,5-tris(4-hydroxyphenyl)benzene, 1,1,1-tris(4-hydroxyphenyl)ethane, or 3,3 - bis(4-hydroxyaryl) hydroxyindole (= isatin bisphenol), 5-chloroindole, 5,7-dichloropurine, 5-bromine blush, etc. Part of a family of dihydroxy compounds The substitution may be carried out in an amount of from 0.01 to 10 mol%, preferably from 0.1 to 2 mol%, based on the dihydroxy compound.

When the molecular weight is to be adjusted, a monovalent aromatic hydroxy compound can be used. The monovalent aromatic hydroxy compound may, for example, be an aromatic (m-) and p-(p-) cresol, m- and p-cresol, p-tert-butylphenol, or a long-chain alkyl-substituted phenol. Family of monohydroxy compounds.

The aromatic polycarbonate resin is preferably a polycarbonate resin derived from 2,2-bis(4-hydroxyphenyl)propane or from 2,2-bis(4-hydroxybenzene). a polycarbonate copolymer derived from propane and other aromatic dihydroxy compounds. The polymer or oligomer having a decane structure can be copolymerized. These aromatic polycarbonate resins can be used in combination of two or more kinds.

The molecular weight of the aromatic polycarbonate resin is dichloromethane as a solvent, and the viscosity average molecular weight converted from the solution viscosity measured at a temperature of 25 ° C is from 16,000 to 30,000, preferably from 18,000 to 28,000. If the viscosity average molecular weight exceeds the upper limit, the fluidity may not be sufficient. If the lower limit is not reached, the impact resistance may not be sufficient.

(b) Styrene/(meth)acrylonitrile-based copolymer:

In the (b) styrene/(meth)acrylonitrile-based copolymer of the present invention, at least a styrene-based monomer and a (meth)acrylonitrile-based monomer are polymerized in the presence of a rubber, if necessary, Further, the styrene/(meth)acrylonitrile-based copolymer can be polymerized together with other monomers copolymerized with the styrene monomer and the (meth)acrylonitrile monomer. Further, the styrene/(meth)acrylonitrile-based copolymer is not limited to the above two or more kinds of monomers all grafted with rubber. Graft polymerization to form a graft copolymer. On the other hand, a mixture of copolymers in which only two or more kinds of the above monomers are copolymerized with each other is usually contained in a large amount together with the graft copolymer.

In the (b) styrene/(meth)acrylonitrile-based copolymer in the present invention, depending on the type of the rubber and the monomer to be formed, ABS resin, AES (alkyl ethoxy sulphuric acid) may be mentioned. Ester) resin, AAS (acrylate-acrylonitrile-styrene) resin, and the like. Further, the method for producing such a copolymer may, for example, be a known method such as emulsion polymerization, solution polymerization, suspension polymerization, or bulk polymerization. .

(b) a blending amount of a styrene/(meth)acrylonitrile-based copolymer, (a) an aromatic polycarbonate resin, and (b) at least a styrene monomer in the presence of a rubber a styrene/(meth)acrylonitrile-based copolymer obtained by polymerizing an acrylonitrile-based monomer, and (b') at least a styrene-based monomer and a (meth)acrylonitrile-based monomer in the presence of a rubber The total amount of the styrene/(meth)acrylonitrile-based copolymer to be polymerized is from 4 to 39 parts by weight, preferably from 10 to 35 parts by weight, based on 100 parts by weight. When the amount of the (b) styrene/(meth)acrylonitrile-based copolymer is more than the upper limit, the impact resistance is liable to lower. If the lower limit is not reached, the fluidity is liable to lower.

(b') Styrene/(meth)acrylonitrile-based copolymer:

In the present invention, (b) at least a styrene-based monomer and a (meth)acrylonitrile-based monomer are polymerized in the presence of a rubber to form a styrene/(meth)acrylonitrile-based copolymer, which is not used in a single manner. And must (b') not in the presence of rubber At least a styrene monomer and a (meth)acrylonitrile monomer are polymerized, and if necessary, other monomers copolymerized with the styrene monomer and the (meth)acrylonitrile monomer are also polymerized together. The obtained styrene/(meth)acrylonitrile-based copolymer is blended with (a) a polycarbonate resin, for example, in combination with an AS (acrylonitrile-styrene) resin or the like. However, among the two components (b) and (b') used together, the monomer units constituting these may be the same species or may be heterologous.

(b') a blending amount of a styrene/(meth)acrylonitrile-based copolymer, which is (a) an aromatic polycarbonate resin, and (b) at least a styrene monomer in the presence of a rubber ( a styrene/(meth)acrylonitrile-based copolymer obtained by polymerizing a methyl)acrylonitrile monomer, and (b') at least a styrene monomer and a (meth)acrylonitrile in the presence of a rubber The total amount of the styrene/(meth)acrylonitrile-based copolymer to be polymerized is 100 parts by weight, preferably 1 to 36 parts by weight, preferably 3 to 25 parts by weight. When the amount of the (b') styrene/(meth)acrylonitrile-based copolymer is more than the upper limit, the impact resistance is liable to lower. If the lower limit is not reached, the fluidity is liable to lower.

The styrene monomer may, for example, be styrene, α-methylstyrene or p-methylstyrene, and is preferably styrene. The (meth)acrylonitrile-based monomer may, for example, be acrylonitrile or methacrylonitrile.

The monomer copolymerizable with the styrene monomer and the (meth)acrylonitrile monomer may, for example, be methyl acrylate, ethyl acrylate, propyl acrylate, methyl methacrylate or methyl group. An alkyl (meth)acrylate such as ethyl acrylate, maleimide, N-phenylmaleimide or the like is preferable, and an alkyl (meth)acrylate is preferred.

The rubber is preferably a rubber having a glass transition temperature of 10 ° C or lower. Specific examples of the rubber include a dien rubber, an acrylic rubber, an ethylene-propylene rubber, and a silicone rubber. Among them, from the viewpoint of balance between performance and cost, it is preferred to select a diene-based rubber or an acrylic rubber.

The di-alkenyl rubber may, for example, be a polybutadiene, a butadiene/styrene copolymer, a polyisoprene, a butadiene/(meth)acrylic lower alkyl ester copolymer, or a dibutylene An olefin/styrene/lower alkyl (meth)acrylate copolymer or the like, and a lower alkyl (meth)acrylate may, for example, be methyl acrylate, ethyl acrylate, methyl methacrylate or the like. Lower alkyl (meth) acrylate in butadiene/(meth)acrylic acid lower alkyl ester copolymer or butadiene/styrene/(meth)acrylic acid lower alkyl ester copolymer The ratio is preferably 30% by weight or less based on the weight of the rubber.

The acrylic rubber may, for example, be an alkyl acrylate rubber, and the alkyl group preferably has 1 to 8 carbon atoms. Specific examples of the alkyl acrylate rubber include ethyl acrylate, butyl acrylate, and ethyl hexyl acrylate. In the alkyl acrylate rubber, a crosslinkable ethylenic unsaturated monomer can be used arbitrarily, and the crosslinking agent may, for example, be an alkyl (meth) acrylate or a poly (meth) acrylate. Divinylbenzene, trivinylbenzene, triallyl cyanurate, allyl (meth)acrylate, succinic acid, isoprene, and the like. The acrylic rubber is exemplified by a core-shell type polymer having a crosslinked diene rubber as a core.

(c) Phosphorus retarder:

The (c) phosphorus-based flame retardant in the present invention is a compound containing phosphorus in the molecule, and preferably a phosphorus-based compound represented by the following general formula (1) or (2).

(wherein R ¹ , R ² and R ³ each represent an alkyl group having 1 to 6 carbon atoms or an aryl group having 6 to 20 carbon atoms which may be substituted by an alkyl group, and h, i and j respectively represent 0 or 1).

The phosphorus-based compound represented by the above general formula (1) can be produced from phosphorus oxychloride or the like by a known method. Specific examples of the phosphorus-based compound represented by the general formula (1) include triphenyl phosphate, tricresyl phosphate, diphenyl-2-ethylmethyl phosphate, and tris(isopropylbenzene) phosphate. Ester), diphenyl methylphosphonate, diethyl phenylphosphonate, diphenylmethylphenyl phosphate, tributyl phosphate, and the like.

(wherein R ⁴ , R ⁵ , R ⁶ and R ⁷ each represent an alkyl group having 1 to 6 carbon atoms or an aryl group having 6 to 20 carbon atoms which may be substituted by an alkyl group, and p, q, r and s are respectively 0 or 1, t is an integer from 1 to 5, and x represents an exoaryl group).

a phosphorus compound represented by the above general formula (2), wherein t is 1 to 5 The condensed phosphate ester, and for a mixture of condensed phosphates of different t, t is the average of its mixtures. x represents an alkylene group which is a divalent group derived from a dihydroxy compound such as resorcinol, hydroquinone or bisphenol A. In a specific example of the phosphorus compound represented by the general formula (2), when resorcin is used as the dihydroxy compound, phenyl resorcinol ‧ polyphosphate, tolyl phthalate Phenol ‧ polyphosphate, phenyl ‧ tolyl ‧ resorcinol ‧ polyphosphate, xylyl benzene resorcinol ‧ polyphosphate, phenyl - p-tert-butyl phenyl ‧ resorcinol Polyphosphate, phenyl ‧ cumene ‧ resorcinol ‧ polyphosphate, tolyl dimethyl benzene resorcinol ‧ polyphosphate, phenyl ‧ cumyl ‧ diisopropyl phenyl ‧ Resorcinol ‧ polyphosphate and so on.

The (c) phosphorus-based flame retardant in the present invention may be a phosphonic acid phosphate compound. Such a compound is selected from at least one selected from the group consisting of a cyclic phenoxy phosphocreatine compound, a chain phenoxy phosphocreatine compound, and a crosslinked phenoxy phosphocreatine compound.

The amount of the phosphorus-based flame retardant is a mixture of (a) an aromatic polycarbonate resin and (b) at least a styrene monomer and a (meth)acrylonitrile monomer in the presence of a rubber. a styrene/(meth)acrylonitrile-based copolymer, and (b') polymerize at least a styrene-based monomer and a (meth)acrylonitrile-based monomer in the presence of a rubber to form a styrene/(methyl) group. The total amount of the acrylonitrile-based copolymer is from 0 to 40 parts by weight, preferably from 3 to 30 parts by weight, more preferably from 5 to 25 parts by weight. When the blending amount of the phosphorus-based flame retardant exceeds the upper limit, the mechanical properties are lowered.

(d) fluorinated polyolefin:

The (d) fluorinated polyolefin in the present invention may, for example, be a fluorinated polyethylene, preferably a polytetrafluoroethylene having a fibril-forming ability, which is easily dispersed. Among the polymers, there is a tendency to bond the polymers to each other to form a fibrous material. Polytetrafluoroethylene having a fine fiber forming ability is classified into the type 3 in the ASTM (American Society for Testing and Materials) specifications. For the polytetrafluoroethylene having a fine fiber forming ability, for example, from San Francisco, Dupont Fluorine Chemical Co., Ltd., as Teflon (registered trademark) 6J or Teflon (registered trademark) 30J, Or it is marketed by Daikin Industries (shares) under the name of Polyflon.

The amount of the fluorinated polyolefin is (a) an aromatic polycarbonate resin, and (b) at least a styrene monomer and a (meth)acrylonitrile monomer are polymerized into a benzene in the presence of a rubber. Ethylene/(meth)acrylonitrile-based copolymer, and (b') polymerized at least styrene-based monomer and (meth)acrylonitrile-based monomer in the presence of rubber to form styrene/(meth)acrylic acid The total amount of the nitrile-based copolymer is from 0 to 5 parts by weight, preferably from 0.02 to 4 parts by weight, more preferably from 0.03 to 3 parts by weight. If the blending amount of the fluorinated polyolefin exceeds the upper limit, the appearance of the molded article may be unfavorable.

(e) Inorganic filler:

The (e) inorganic filler in the present invention is not particularly limited, and a conventional inorganic filler used can be exemplified. Specifically, glass fiber, glass flake, glass beads, mild glass, hollow glass, talc, clay, mica, carbon fiber, and wollastonite can be exemplified. , potassium titanate whiskers (whisker), titanium oxide whiskers, zinc oxide whiskers, etc., from the appearance, soft glass, talc, clay, ash, etc., which are preferably measured by laser diffraction method The number average particle diameter is 9.0 μm or less, and the content of the Fe (iron) component and the Al (aluminum) component in the talc is 0.5% by weight or less of Fe ₂ O ₃ or Al ₂ O ₃ , respectively, and the surface-treated talc is not more than 0.5% by weight. More useful.

The inorganic filler is formulated in an amount of (a) an aromatic polycarbonate resin, and (b) at least a styrene monomer and a (meth)acrylonitrile monomer are polymerized into a styrene in the presence of a rubber. /(Meth)acrylonitrile-based copolymer, and (b') polymerize at least a styrene monomer and a (meth)acrylonitrile monomer in the presence of a rubber to form a styrene/(meth)acrylonitrile The total copolymer is 100 parts by weight, preferably 0 to 50 parts by weight, preferably 1 to 40 parts by weight, more preferably 3 to 30 parts by weight. When the blending amount of the inorganic filler exceeds the upper limit, the appearance of the molded article and the impact strength are lowered, which is not preferable.

The AS area and the average occupied area of the rubber particles measured by electron micrograph image processing of the composition Sd, Sg: the resin composition of the present invention or a molded article thereof is usually composed of (a) component-aromatic polymerization The carbonate resin-formed continuous phase (referred to as "matrix" in the present specification) is dispersed in the component (b) - at least the styrene monomer in the presence of rubber Polymerization of acrylonitrile-based monomer to styrene/(meth)acrylonitrile-based copolymer and (b') component - at least styrene monomer and (meth)acrylonitrile in the presence of rubber a majority of the non-continuous phase formed by the polymerization of a monomer to a styrene/(meth)acrylonitrile-based copolymer (in the present specification, the component (b) is derived or derived from (b) The ') component, which is referred to as the "AS field" in the AS field, has the morphology of those who do not contain rubber particles. In such a state, an appropriate dyeing technique using a two-stage dyeing method using osmium tetroxide (OsO ₄ ) and ruthenium tetroxide (RuO ₄ ) can be easily confirmed by an electron microscope.

That is, in the transmission electron microscope observation after the two-stage dyeing, as shown in the attached FIG. 1 or FIG. 4, the (A) gray matrix and the (B) bright-colored AS field can be separately recognized. (C) Three kinds of dark discontinuous phases in the bright AS field. Among these, (C) a dark discontinuous phase is a dye which is caused by osmium tetroxide in a rubber obtained by graft polymerization or non-graft polymerization of the above two monomers.

Here, the inventors of the present invention have such a morphology of the composition, in particular, between (B) the bright-colored AS field and (C) the dark discontinuous phase (rubber particles), the average occupied area, and the fusion strength. The results of the relevance review. Get a certain conclusion. In other words, when the total weight ratio of the component (b) component + (b') component of the total weight of the component (a) component + (b) component + (b') component is Bwt, the mode is as described above. The average occupied area Sd (μm ² ) of the AS field dispersed in the polycarbonate resin matrix measured by electron micrograph image processing of the dyed composition, and the average occupied area of the rubber particles dispersed in the AS field The value of Sg/(Sd/B ^2/3 ) of the number of turns between Sg (μm ² ) needs to be 0.5 or more, that is, Sd and Sg need to conform to the following relation (1).

[Number 2] Sg/(Sd/B ^2/3 ) ≧ 0.5 (1)

The value of the above relational expression (1) is preferably 0.55 or more, more preferably 0.6 or more. In the above relational expression (1), the Sd value is, for example, a variety of numerical values depending on the composition ratio of the resin composition, the production conditions, the type of the component (b), and the type of the component (b'), or the production method, and Sg/( The larger the value of Sd/B ^2/3 ), the larger the ratio of the rubber particle size Sg of the AS field diameter Sd. The present inventors have found that the fact that the welding strength is improved as the object of the present invention can be achieved if the conditions of the relationship (1) can be satisfied. In particular, in the determination of the Sg/(Sd/B ^2/3 ) value, attention is paid to two kinds of styrene/(meth)acrylonitrile-based copolymers constituting the component (b) and the component (b'). The composition ratio of the monomer unit of the substance, and the result of a correlation study with the Sg/(Sd/B ^2/3 ) value, as found in the monomer unit constituting the component (b) and the component (b') The composition is very different, that is, when the following relationship (3) is satisfied, the fact that the resin composition having the desired weld strength and its molded article can be obtained can be obtained.

[Number 3]|Ab-Ab’|≧3 (3)

The value of the above relational expression (3) is preferably 4 or more, and more preferably 5 or more. Here, Abwt% means the weight ratio of the (meth)acrylonitrile-based monomer unit which is a total weight of the styrene monomer unit + (meth)acrylonitrile monomer unit constituting the component (b). And Ab'wt% means the (meth)acrylonitrile-based monomer unit of the total weight of the styrene monomer unit + (meth)acrylonitrile monomer unit constituting the (b') component. Weight ratio.

When the component (b) and the component (b') satisfying such conditions are used in combination, it is difficult to be compatible with the AS field derived from the component (b) and the AS region derived from the (b') component, and it becomes difficult. The tendency to form a large AS field becomes a situation that easily conforms to the above relationship (1).

For example, when the weight ratio of the (meth)acrylonitrile monomer in the component (b) is 26 wt%, the (meth)acrylonitrile monomer in the (b') component is due to compatibility. The weight ratio is generally also used to the same extent, that is, the Ab'wt% is 26 wt%. However, in the present invention, the composition ratio of the monomer unit of the component (b) and the component (b') which are generally not used in combination is very different, and the dispersibility in the AS field can be improved. A high weld strength is exhibited. Further, even in the case of a resin composition containing an inorganic filler which is generally considered to have a reduced strength, a high welding strength can be maintained.

In the present invention, an electron micrograph of the composition dyed as described above is subjected to image processing to determine an average occupied area Sd of the AS field dispersed in the polycarbonate resin matrix and rubber particles dispersed in the AS field. The step of averaging the area Sg is approximately as follows.

(1) Digital micrographs (analog information) are digitized to produce monochrome image information.

(2) From the monochrome image information, the specific information is taken out, and the measurement image information is created. The specific information that needs to be taken out can be used to measure the area of the individual AS area or the area occupied by the rubber particles (B) the shape and size of the contour of the bright-colored AS field or (C) dark rubber particles.

(3) Measuring individual AS areas or rubber pellets from measurement image information The occupied area of the child, and the average occupied area (Sd) or (Sg) of the number average is calculated.

Here, in the measurement steps of the above (1) to (3), (4) and (5) required for data sorting described below are carried out in consideration of the correlation with the welding strength.

(4) Except for the calculation of the number average value if the measured area or particle having an area of 0.01 μm ² or less is measured.

(5) In the measurement step of Sg, the area of the (B) bright color AS region existing in the outline of the (C) dark rubber particles is also included in the occupied area of the rubber particles.

Method for producing polycarbonate resin composition:

The method for producing the polycarbonate resin composition of the present invention is as long as it is an AS field dispersed in a composition measured by electron micrograph image processing of the composition and rubber particles dispersed in the AS field. When the average occupied area Sd and Sg can meet the predetermined requirements, it is not particularly limited, and examples thereof include an aromatic polycarbonate resin, (b), and (b') two kinds of styrene/(meth) propylene. a method of melt-kneading a nitrile copolymer, a phosphorus-based flame retardant, and polytetrafluoroethylene; and pre-kneading an aromatic polycarbonate resin, two kinds of styrene/(meth)acrylonitrile-based copolymer, and polytetrafluoroethylene After that, the flame retardant is supplied and kneaded from the middle of the extruder.

It is also possible to adjust the average occupied area by the type or production method of the two types of styrene/(meth)acrylonitrile-based copolymers (b) and (b') which are blended in the (a) aromatic polycarbonate resin. Sg, and preferably paired to constitute the above component (b) The weight ratio (Ab wt%) of the total weight of the (meth)acrylonitrile monomer unit of the styrene monomer unit + (meth)acrylonitrile monomer unit, and the composition of the above (b') The weight ratio (Ab'wt%) of the (meth)acrylonitrile-based monomer unit of the total weight of the styrene monomer unit + (meth)acrylonitrile monomer unit can satisfy the following relationship (3) ).

[Number 4]|Ab-Ab’|≧3 (3)

The value of the above relational expression (3) is preferably 4 or more, and more preferably 5 or more.

In the polycarbonate resin composition of the present invention, if necessary, a stabilizer such as a UV absorber or an oxidation inhibitor, a pigment, a dye, a lubricant, a mold release agent, a plasticizer, a charge prevention agent, and a slidability improver may be added. Additives such as elastomers, compatibilizers, and other flame retardants. These addition methods can be suitably added in accordance with a method known for exerting such characteristics.

In the polycarbonate resin composition of the present invention, in addition to the aromatic polycarbonate resin of the component (a) and the two styrene/(meth)acrylonitrile-based copolymers of the components (b) and (b'), A thermoplastic resin such as a polyester resin such as polybutylene terephthalate or polyethylene terephthalate, a polyamide resin, a polyphenylene ether resin or a polyolefin resin may be blended. The blending amount of the thermoplastic resin other than the aromatic polycarbonate resin and the two kinds of the styrene/(meth)acrylonitrile-based copolymer is preferably 40% by weight or less, and more preferably 30% by weight or less.

The polycarbonate resin composition of the present invention, preferably a non-halogen polycarbonate resin composition, and the components formulated in the composition of the present invention are composed of In the case of corrosion of the molding machine or the metal mold, environmental protection problems, etc., it is preferably a non-halogen or a halogen content.

The method for forming a polycarbonate resin composition of the present invention is not particularly limited, and a molding method for a thermoplastic resin, that is, injection molding, hollow molding, and extrusion can be applied. Forming methods such as extrude moulding, press moulding, sheet moulding, thermal forming, rotational moulding, laminate moulding, etc. Jia is injection molded.

Example

In the following, the present invention will be described in more detail by way of examples, but the present invention is not intended to be limited thereby. In the examples and comparative examples, the materials described below were used.

(1) Polycarbonate Resin-1: Poly-4,4-isopropylidenebiphenyl carbonate, "Ublon S-2000" manufactured by Mitsubishi Engineering Plastics Co., Ltd., and viscosity average molecular weight 25,000. (hereinafter, referred to as "PC-1").

(2) Polycarbonate Resin-2: Poly-4,4-isopropylidenebiphenyl carbonate, "Ublon S-3000" manufactured by Mitsubishi Engineering Plastics Co., Ltd., and viscosity average molecular weight 22,000. (hereinafter, referred to as "PC-2").

(3) ABS resin: Epoxy polymerization ABS resin, rubber type polybutadiene, technology polymer (unit) "DP-611", AN (acrylonitrile) ratio 26%

(4) AS resin-1: "SAN-T" and AN ratio of AS resin and technology polymer (share) 34%

(5) AS resin-2: "SAN-R" and AN ratio of AS resin and technology polymer (share)

(6) AS resin-3: "SAN-C" and AN ratio of AS resin and technology polymer (share)

(7) Flame retardant: condensed phosphate ester represented by the following formula (3) (wherein t ₂ = 1.08), "FP-700" manufactured by Asahi Kasei Co., Ltd.

(8) Polytetrafluoroethylene (PTFE): "Teflon F-201L" made by Taijin (stock)

(9) Inorganic filler: talc, number average particle diameter 4.9μm, no surface treatment, Lin Huacheng (share) system "micron white 5000S"

In addition, the physical property evaluation of the test piece was carried out as described below.

(10) Tensile strength: According to ISO (International Organization for Standardization) 527-1 and 2, a tensile test was carried out using a 1 A test piece having a thickness of 4 mm at a test speed of 50 mm/min. Here, when forming the test piece to be welded, a metal mold having a two-point gate in the longitudinal direction of the test piece and a center gate line (the distance between gates is 170 mm) is used, and the welded portion is formed at the center portion. The tensile test was carried out under the same conditions without welding. The test results are based on the test piece. The type is expressed as a tensile strength, a welded tensile strength, and a welded tensile strength. Further, for the purpose of the evaluation of the fusion strength, when the weld tensile strength and the fusion tensile strength are stayed, the percentage of the tensile strength is calculated and expressed as the respective retention ratios.

(11) Fluidity: using a bar-flow metal mold (thickness 2 mm, width 20 mm, 1.5 mm pin-hole gate, cylinder temperature set 240 ° C, mold set temperature 60 ° C, injection pressure 100 MPa, injection time 5 seconds, molding cycle 45 seconds, The flow length (in mm) was measured.

(12) Transmission electron microscope observation:

[ultra-thin section]

The slice is cut out from the sample pellets in such a manner that the surface perpendicular to the direction in the center of the strand direction is formed as an end surface. Ultra-thin sections were prepared by cutting with diamonds according to an ultra microtome (LEICA) and ULTRACUT UCT equipped with a sample cooling device (fryo unit). The cutting conditions were set at a room temperature of -100 ° C and an ultrathin section thickness of 100 nm.

[2 sections of dyeing]

After the ultrathin sections were stowed on a copper grid, two sections of dyeing were performed using iron oxide and osmium tetroxide. As a result of the dyeing, polycarbonate can be observed as a gray matrix (A), a styrene/(meth)acrylonitrile copolymer can be observed as a bright color (B), and a butadiene rubber can be used. The A dark discontinuous phase (C) in a brightly colored field was observed.

[electron microphoto photography]

The ultrathin sections which were dyed were observed using a transmission electron microscope ("1200EXII" type manufactured by JEOL Ltd.) at an acceleration voltage of 100 Kv and a magnification of 5,000 times. Photographic photography was carried out at the time of observation, and images were recorded on a film FG (size: 5.9 × 8.2 cm) for electron microscopy manufactured by Fuji Photo Film Co., Ltd. The range of images recorded is approximately 11 x 15 μm.

[Image Processing]

Image recorded on a negative film (nega-film) by photo photography, using a film scanner (Konica) Minolta Imaging Co., Ltd.: Dimage Scan Multi (Image Scan) The aiming multiple) F-3000 type) makes it digital. The digitization system is implemented at 564 dpi (dot/吋) to produce a monochrome image file of approximately 1,240 × 1,800 pixels.

AS field:

The obtained monochrome image file is processed by "photo shop" (photographing station) (version 7 (ver. 7)) manufactured by Adobe (Atobi) Co., Ltd., and the data of the AS field is extracted and made binary. (binary) measurement image (refer to attached figure 2 or figure 5). In the AS field, the data extraction and binarization criteria are based on (1) the data of the (B) bright color field is used as the "AS field" by the above two kinds of dyeing results. At this time, the (C) dark rubber particles present in the (B) bright color field are also included. Contained in the "AS field" of the occupied area. (2) Threshold hold value, which is based on the bright color of only the "AS field", while the darker (A) gray matrix and (C) dark rubber particles are not selected. , set to the value of appropriate brightness.

From the above-mentioned measurement image, "Image Pro Plus" (Version 4.0 (ver. 4.0)) manufactured by Media Cybernetics was used to measure the area occupied by the AS field. When the measurement is performed, the length on the screen is corrected based on the scale recorded on each image at the time of photographing, and the measurement is performed in the dotted line frame in the figure. When the occupied area and the number of the AS areas measured in this manner are totaled, the average value of the occupied area is calculated as the average occupied area Sd. At this time, among the areas occupied by the measurement, in the range of 0.01 μm ² or less, the calculation of the numerical average is excluded.

Rubber particles:

The obtained monochrome image file is processed by "photo shop" (ver. 7) manufactured by Adobe Co., Ltd., and a measurement image obtained by binarizing the rubber particles is prepared (refer to attached figure 3 or 6 figure). The data extraction and binarization criteria of the rubber particles are based on the results of the above two stages of dyeing, and the data of the (C) dark discontinuous phase is extracted as "rubber particles". At this time, the field of (B) bright color existing inside (C) is also included in the occupied area of "rubber particles". (2) The threshold for binarization is selected by selecting only the dark color of "rubber particles", while the brighter (A) gray matrix and (B) bright color fields are not selected. The value of the appropriate brightness.

From the measurement image described above, "Image Pro Plua" (Ver. 4.0) manufactured by Media Cybernetics Co., Ltd. was used to measure the occupied area of the rubber particles. When the measurement is performed, the length on the screen is corrected based on the scale recorded on each image at the time of shooting, and the measurement is performed in the dotted line frame in the figure. After the total area and the number of the rubber particles measured in this manner are totaled, the average value of the occupied area is calculated as the average occupied area Sg. At this time, among the measured occupied areas, particles of 0.01 μm ² or less are excluded from the calculation of the number average value.

[Examples 1 to 4, Comparative Examples 1 to 3]

The components other than the flame retardant were removed, and the ratio (weight ratio) shown in Table 1 was adjusted, and after mixing for 20 minutes using a tumbler, the diameter of the screw was 32 mm, L/D = 42. In a twin-screw extruder ("TEX-30 HSST" manufactured by Nippon Steel Co., Ltd.), kneading was carried out at a barrel setting temperature of 250 ° C, a screw setting rotation number of 250 rpm, and a set extrusion amount of 20 kg / hour. When a flame retardant is added, liquid injection is carried out from the middle of the twin-screw extruder in the ratio (weight ratio) shown in Table 1.

After the pellets obtained by cutting the extruded strands were dried at 80 ° C for 5 hours, an injection molding machine ("SG-75" manufactured by Sumitomo Heavy Industries, Ltd.) was used, and the cylinder temperature was 250 ° C, and the metal mold was used. The temperature was 70 ° C and the molding cycle was 60 seconds, and the 1A-shaped test piece which was not welded and welded was formed, and the tensile strength and the tensile strength of the welded joint were evaluated. Similarly, the obtained pellets were dried at 80 ° C for 5 hours, and then an injection molding machine (manufactured by Sumitomo Heavy Industries Co., Ltd.) was used. "SG-75"), a welded 1A-shaped test piece was formed at a cylinder temperature of 300 ° C, a mold temperature of 70 ° C, and a molding cycle of 180 seconds, and the weld tensile strength stay was evaluated. Table 1 shows the evaluation results of the respective examples and comparative examples.

From the above results, we can see that The (a) aromatic polycarbonate resin component + (b) polymerizes at least a styrene monomer and a (meth)acrylonitrile monomer in the presence of a rubber to form a styrene/(meth)acrylonitrile The copolymer component + (b') does not polymerize the styrene monomer and the (meth)acrylonitrile monomer in the presence of rubber to form a total weight of the styrene/(meth)acrylonitrile copolymer component. When the total weight ratio of the component (b) and the component (b') is Bwt%, the average occupied area of the AS region dispersed in the polycarbonate resin matrix measured by electron micrograph image processing of the composition is Sd. In addition, the average occupied area Sg of the rubber particles dispersed in the AS field can satisfy the following formula (1), and the value of the weld strength retention rate is high.

[Number 5] Sg/(Sd/B ^2/3 ) ≧ 0.5 (1)

On the other hand, even if the adjustment ratio of each component (a) to (e) conforms to the composition of the predetermined requirement of the present invention, if the formula (1) is not satisfied, the weld strength retention ratio will still show a low value. In addition, when the relationship (1) is satisfied, the total weight of the (meth)acrylonitrile monomer unit constituting the styrene monomer unit + (meth)acrylonitrile monomer unit of the component (b) is The weight ratio of the bulk unit (Ab wt%) and the (meth)acrylonitrile monomer to the total weight of the styrene monomer unit + (meth)acrylonitrile monomer unit constituting the (b') component The weight ratio of the unit (Ab'wt%) can be achieved by meeting the following reference formula (3).

[Number 6]|Ab-Ab’|≧3 (3)

[Injection molded product]

Using the pellets obtained in Example 3 and Comparative Example 2, a box shape having an outer dimension of 150 mm × 150 mm × 20 mm and a section thickness of 2 mm was used. 1.5 mm 4-point gate metal mold (coordinates at the gate position are 25 mm, 75 mm on the 150 mm × 150 mm surface; 75 mm, 25 mm; 75 mm, 125 mm; 125 mm, 75 mm) Injection molding. The molded article obtained in Example 3 had no problem in terms of appearance, warpage, and rigidity including welding. However, the molded article obtained in Comparative Example 2 was inferior in the appearance of welding, and when the force was applied, it was damaged at the welded portion.

Fig. 1 is an electron micrograph of an ultrathin section of the pellet obtained in Example 1.

Fig. 2: Image of Sd measurement produced from Fig. 1.

Fig. 3: Image of Sg measurement produced from Fig. 1.

Fig. 4 is an electron micrograph of an ultrathin section of the pellet obtained in Comparative Example 1.

Fig. 5: Image of Sd measurement produced from Fig. 4.

Fig. 6: Image of the Sg measurement produced from Fig. 4.

Claims (8)

A polycarbonate resin composition which is a mixture of (a) an aromatic polycarbonate resin of 60 to 95 parts by weight, (b) at least a styrene monomer and a (meth)acrylonitrile in the presence of a rubber 4 to 39 parts by weight of the styrene/(meth)acrylonitrile-based copolymer formed by the bulk polymerization, and (b') polymerized at least the styrene monomer and the (meth)acrylonitrile monomer in the presence of the rubber. 1 to 36 parts by weight of the total of 100 parts by weight of the styrene/(meth)acrylonitrile-based copolymer, 0 to 40 parts by weight of (c) phosphorus-based flame retardant, and 0 to 5 parts by weight of (d) fluorinated polyolefin And (e) a polycarbonate resin composition of 0 to 50 parts by weight of the inorganic filler; characterized by: a total weight of the component (a) component + (b) component + (b') When the total weight ratio of the component (b) and the component (b') is B wt%, the styrene/(methyl group) dispersed in the polycarbonate resin matrix measured by electron micrograph image processing of the composition ) average area occupied by the field acrylonitrile copolymer (hereinafter referred to as "aS art") is Sd (μm ^2), the average area occupied by the dispersion of the rubber particles in the art aS Sg (μm ²⁾ based The following relational expression (1): (meth)acrylonitrile-based monomer unit having a total weight of the styrene monomer unit + (meth)acrylonitrile monomer unit constituting the component (b) Weight ratio (Ab wt%) and (meth)acrylonitrile monomer unit to the total weight of the styrene monomer unit + (meth)acrylonitrile monomer unit constituting the above (b') component The weight ratio (Ab'wt%) is in accordance with the following relationship (3); [Number 1] Sg / (Sd / B ² / ³ ) ≧ 0.5 (1) [Number 3] | Ab-Ab' | ≧ 3 (3). The polycarbonate resin composition of claim 1, wherein B, Sd, and Sg satisfy the following relationship (2), [2] Sg/(Sd/B ^2/3 ) ≧ 0.6 (2) . In the polycarbonate resin composition of the first aspect of the invention, wherein the (b) component and the (b') component, the Ab and Ab' systems conform to the following relationship (4) [number 4] | Ab-Ab '|≧5 (4). The polycarbonate resin composition of claim 1, wherein the aromatic polycarbonate resin has a viscosity average molecular weight of from 16,000 to 30,000. The polycarbonate resin composition according to claim 1, wherein the phosphorus-based flame retardant is a phosphorus-based compound represented by the following general formula (1) or (2). (wherein R ¹ , R ² and R ³ each represent an alkyl group having 1 to 6 carbon atoms or an aryl group having 6 to 20 carbon atoms which may be substituted by an alkyl group, and h, i and j respectively represent 0 or 1) , (wherein R ⁴ , R ⁵ , R ⁶ and R ⁷ each represent an alkyl group having 1 to 6 carbon atoms or an aryl group having 6 to 20 carbon atoms which may be substituted by an alkyl group, and p, q, r and s respectively Is 0 or 1, t is an integer from 1 to 5, and x represents an arylene group). The polycarbonate resin composition of claim 1, wherein the inorganic filler is talc. A molded article obtained by injection molding a polycarbonate resin composition according to any one of claims 1 to 6. The molded article of claim 7, wherein the molded article is injection molded by a multi-point gate.